JP2020109817A - Semiconductor light-emitting element and method of manufacturing the same - Google Patents

Abstract

To provide a semiconductor light-emitting element having improved light emission output.SOLUTION: The semiconductor light-emitting element includes a laminated structure in which a first III-V compound semiconductor layer having a different composition ratio and a second III-V compound semiconductor layer are repeatedly laminated. Each of the first and second III-V compound semiconductor layers is composed of three or more elements selected from Al, Ga and In, and As, Sb and P. A composition wavelength difference between a composition wavelength of the first III-V compound semiconductor layer and a composition wavelength of the second III-V compound semiconductor layer is 50 nm or less. A ratio of a lattice constant difference between a lattice constant of the first III-V compound semiconductor layer and a lattice constant of the second III-V compound semiconductor layer is 0.05% or more and 0.60% or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a semiconductor light emitting device and a method for manufacturing a semiconductor light emitting device.

A III-V group compound semiconductor such as InGaAsP is used as a semiconductor material of a semiconductor layer in a semiconductor light emitting device. By adjusting the composition ratio of the light emitting layer formed of the III-V group compound semiconductor material, it is possible to widely adjust the emission wavelength of the semiconductor light emitting element from green to infrared. For example, an infrared-emitting semiconductor light-emitting element having an emission wavelength in the infrared region having a wavelength of 750 nm or more is widely used for applications such as sensors, gas analysis, and surveillance cameras.

Until now, many attempts have been made to improve the characteristics of semiconductor light emitting devices. For example, in Patent Document 1, attention is paid to a difference in lattice constant of each layer in a light emitting layer having a laminated structure formed by laminating a plurality of III-V group compound semiconductor layers.

Patent Document 1 uses a light emitting layer having a quantum well structure composed of a quaternary compound semiconductor layer of InGaAsP. In Patent Document 1, the lattice constant difference is adjusted by changing the composition ratio of each well layer to distort the quantum well, and an attempt is made to increase the output due to the distortion. The composition ratio of each well layer in Patent Document 1 is adjusted so that the emission transition wavelengths become equal.

JP-A-7-147454

In recent years, the applications of semiconductor light emitting devices have been expanding more and more. Therefore, there is a demand for a technique for further improving the light emission output of a semiconductor light emitting device using a III-V group compound semiconductor as a light emitting layer material.

Therefore, an object of the present invention is to provide a semiconductor light emitting device having an improved light emission output. A further object of the present invention is to provide a method for manufacturing this semiconductor light emitting device.

As a result of earnest studies to solve the above problems, the present inventors have found that the composition wavelength between layers in a light emitting layer having a laminated structure formed by laminating first and second III-V compound semiconductor layers. Attention was paid to the difference and the lattice constant difference. Then, it has been found that the light emission output of the semiconductor light emitting device can be improved by providing the laminated structure in which the difference in the composition wavelength is reduced and the difference in the lattice constant in the appropriate range is provided. The present invention has been completed based on the above findings, and its gist configuration is as follows.

(1) A semiconductor light emitting device comprising a light emitting layer having a laminated structure in which a first III-V compound semiconductor layer and a second III-V compound semiconductor layer having different composition ratios are repeatedly laminated,
The group III element in the first and second group III-V compound semiconductor layers is one or more selected from the group consisting of Al, Ga and In, and the first and second groups The group V element in the III-V group compound semiconductor layer is one kind or two or more kinds selected from the group consisting of As, Sb and P,
Each of the first and second III-V group compound semiconductor layers is composed of three or more elements selected from the group III element and the group V element,
A difference in composition wavelength between the composition wavelength of the first III-V compound semiconductor layer and the composition wavelength of the second III-V compound semiconductor layer is 50 nm or less, and the first III-V A semiconductor light emitting device, characterized in that the ratio of the lattice constant difference between the lattice constant of the group compound semiconductor layer and the lattice constant of the second III-V compound semiconductor layer is 0.05% or more and 0.60% or less. ..

(2) The semiconductor light emitting device according to (1), wherein the ratio of the lattice constant difference is 0.3% or more.

(3) The semiconductor light emitting device according to (1) or (2), wherein the composition wavelength difference between the first and second III-V compound semiconductor layers is 30 nm or less.

(4) Each of the first and second III-V group compound semiconductor layers is composed of four or more elements selected from the group III elements and the group V elements (1) ~ The semiconductor light emitting device according to any one of (3).

(5) Among the elements constituting the four or more elements, the group III element is Ga, In, and the group V element is two or more elements selected from the group consisting of As, Sb, P. The semiconductor light emitting device according to 4).

(6) The semiconductor light-emitting device according to any one of (1) to (3), wherein the first and second III-V group compound semiconductor layers are both InGaAsP quaternary compound semiconductors.

(7) In the laminated structure of the light emitting layer, a third III-V group compound semiconductor layer is further provided between the first and second III-V group compound semiconductor layers,
The third group III-V compound semiconductor layer is composed of four or more elements selected from the group III elements and the group V elements,
The composition wavelength difference between the adjacent first, second and third III-V compound semiconductor layers is 50 nm or less, and
The ratio of the difference in lattice constant between the first, second and third III-V group compound semiconductor layers adjacent to each other is 0.05% or more and 0.60% or less. 4. The semiconductor light emitting device according to any one of 1) to 3) above.

(8) The semiconductor light emitting device according to (7), wherein the third III-V compound semiconductor layer is a quaternary compound semiconductor of InGaAsP.

(9) A method for manufacturing the semiconductor light-emitting device according to any one of (1) to (8) above,
A first step of forming the first III-V compound semiconductor layer,
A second step of forming the second III-V compound semiconductor layer,
A method of manufacturing a semiconductor light emitting device, comprising: a light emitting layer forming step of forming the light emitting layer by repeating the first step and the second step.

According to the present invention, it is possible to provide a semiconductor light emitting device having an improved light emission output. Further, the present invention can provide a method for manufacturing the semiconductor light emitting device.

FIG. 3 is a schematic cross-sectional view showing one embodiment of a light emitting layer in a semiconductor light emitting device according to the present invention. It is a schematic cross section which shows another aspect of the light emitting layer in the semiconductor light emitting element according to this invention. FIG. 3 is a schematic cross-sectional view showing a semiconductor light emitting device according to one embodiment of the present invention. It is a graph which compares the light emission output in an Example. It is a graph which compares the forward voltage in an Example.

Prior to the description of the embodiments according to the present invention, various definitions in the present specification will be described.

<III-V compound semiconductor layer>
First, in the present specification, when simply referred to as “III-V group compound semiconductor”, its composition is represented by the general formula: (In _a Ga _b Al _c )(P _x As _y Sb _z ). Here, the following relationships are established regarding the composition ratio of each element.
For group III elements, c=1-ab, 0≦a≦1,0≦b≦1,0≦c≦1
For group V elements, z=1−x−y, 0≦x≦1,0≦y≦1,0≦z≦1
Then, as described later, the III-V group compound semiconductor layer in the light emitting layer is selected from the group consisting of Al, Ga and In, and the group consisting of the group III element and As, Sb and P. It is composed of three or more kinds of elements selected from the group V elements. Since the combination of the three types of elements with the ratio of the lattice constant difference from the growth substrate being 1% or less is limited, it is more preferable to use four or more types of elements. A total of 3 or more of 1 or 2 or more of each composition ratio a, b, c in the above general formula and 1 or 2 or more of x, y, z is at least 0 or more.

ここで、上記式＜２＞において、４つの３元混晶の物性値は非線形因子を考慮しているので、算出される擬４元混晶の物性値も非線形因子が必然的に考慮されていることになる。
次に、本明細書における混晶の格子定数の算出について説明する。格子定数には基板平面に対して垂直方向（成長方向）と水平方向（面内方向）の２種があるところ、本明細書においては垂直方向の値を用いる。まずベガート則に従い混晶の単純な格子定数を計算する。ＩｎＧａＡｓＰ系（すなわち一般式：(In_aGa_b)(P_xAs_y)）を例として例示すると、物性定数Ａ_abxy（ベガート則による格子定数）は、各組成比（固相比）が既知である場合、擬４元混晶の基になる４つの２元混晶の物性定数B_ax, B_bx, B_ay, B_by（下記表１の文献値の格子定数）をもとに下記式＜３＞により計算される。
A_abxy=a×x×B_ax+b×x×B_bx+a×y×B_ay+b×y×B_by ・・・＜３＞ <Composition wavelength and lattice constant based on composition>
In the calculation of the composition wavelength and the lattice constant based on the composition in this specification, reference should be made to Haruo Nagai et al., "Photonics Series 6 III-V Group Semiconductor Mixed Crystals", First Edition, Corona, October 25, 1988. Numerical values (from Table 2.1, the value of the nonlinear factor of the ternary mixed crystal, from Table 2.2, the lattice constant of the binary crystal, from Table 2.3, the elastic stiffness constant of the binary crystal, and from Table 2.7) A binary crystal bandgap, etc.) was used. Although an InGaAsP system will be mainly described below, the case where Al or Sb is contained can be calculated based on the literature values described in the above literature. Hereinafter, among the composition ratios a, b, c, x, y, z, the case of having two kinds from a, b, c and two kinds from x, y, z is referred to as a pseudo quaternary mixed crystal, and a, The case of having 3 types from b, c and 1 type from x, y, z (or 1 type from a, b, c, 3 types from x, y, z) is called a pseudo ternary mixed crystal.
In the present specification, the “composition wavelength” of the III-V compound semiconductor layer is defined by the following formula <1> from the energy band gap Eg based on the composition of the III-V compound semiconductor layer.
Eg=1239.8/λ・・・<1>
Means the wavelength λ converted by When each composition ratio (solid phase ratio) is known, first, the energy band gaps E of the four ternary mixed crystals that are the bases of the pseudo quaternary mixed crystal are obtained using the nonlinear factor of the ternary mixed crystal. Taking the InGaAsP system (that is, the general formula: (In _a Ga _b )(P _x As _y )) as an example, ternary mixed crystals of (Ga,In)P, (Ga,In)As, Ga(P,As) ) And In(P,As), the energy band gap E is calculated in consideration of the nonlinear factor. InP from the respective literature values as a band gap E0 [eV] of the binary: 1.35, GaP: 2.74, InAs : 0.36, GaAs: 1.42, and the literature value as the value of the nonlinear factor (bowing parameters E ₀ [eV]) From (Ga,In)P:0.7, (Ga,In)As:0.51, Ga(P,As):0.3, In(P,As):0.23. For example, the energy band gap E _abx of In _a Ga _b P is
E _abx = 1.35 × a + 2.74 × b‐0.7 × a × b
Calculated as Similar calculations are performed for other ternary mixed crystals.
After calculating the energy band gaps of the four ternary mixed crystals, based on Vegard's law, the physical property value Eg _{abxy of the} quasi _quaternary mixed crystals (In _a Ga _b )(P _x As _y ) Band gap) is _calculated based on the following equation <2> by using the physical property values E _abx, E _aby, E _{axy, and} E _{bxy of} four ternary mixed crystals (energy band gap considering the nonlinear factors obtained above). be able to.

Here, in the above formula <2>, since the physical property values of the four ternary mixed crystals take into consideration the nonlinear factor, the calculated physical property values of the pseudo-quaternary mixed crystal also necessarily take the nonlinear factor into consideration. Will be there.
Next, the calculation of the mixed crystal lattice constant in the present specification will be described. There are two types of lattice constants, a vertical direction (growth direction) and a horizontal direction (in-plane direction) with respect to the plane of the substrate. In this specification, a value in the vertical direction is used. First, a simple lattice constant of a mixed crystal is calculated according to Beggert's law. Taking the InGaAsP system (that is, the general formula: (In _a Ga _b )(P _x As _y )) as an example, the physical property constant A _abxy (lattice constant according to Beggert's law) is known at each composition ratio (solid phase ratio). In some cases, based on the physical constants B _ax , B _bx , B _ay, B _by (lattice constants of the literature values in Table 1 below) of the four binary mixed crystals that form the basis of the pseudo-quaternary mixed crystals, the following formula 3>.
A _abxy = a × x × B _ax + b × x × B _bx + a × y × B _ay + b × y × B _by・・・<3>

Next, also for the elastic constants C11 and C12, the elastic constants C11 _abxy and C12 _abxy of (In _a Ga _b )(P _x As _y ) are calculated in the same manner as the above formula <3>.
If the lattice constant of the growth substrate is a _s , the following formula <4> is applied in consideration of the lattice deformation based on the elastic property of the semiconductor crystal, and the lattice constant a (in the vertical direction) is taken into consideration. You can ask _abxy .
a _abxy =A _abxy ‐2×(a _s -A _abxy )×C12 _abxy /C11 _abxy・・・<4>
Here, in this embodiment, since InP is used as the growth substrate, the lattice constant of the growth substrate may be the lattice constant of InP for a _s .

A_abcy=a×B_ay+b×B_by+c×B_cy ・・・＜６＞
なお、III-V族化合物半導体が３元系、５元系又は６元系の場合で前述と同様の考えに従って式を変形し、組成波長及び格子定数を求めることができる。また、２元系については上記文献に記載の値を用いることができる。 In the case of a quasi-ternary mixed crystal, taking the general formula: (In _a Ga _b Al _c )(As) as an example, the band gap Eg _abcy and the lattice constant A _abcy according to the Beggert rule are obtained from the following formulas <5> and <6>. Can be calculated.

A _abcy = a×B _ay +b×B _by +c×B _cy・・・<6>
When the III-V group compound semiconductor is a ternary system, a quinary system, or a ternary system, the formula can be modified according to the same idea as described above to obtain the composition wavelength and the lattice constant. The values described in the above-mentioned documents can be used for the binary system.

<P-type, n-type and i-type and dopant concentration>
In this specification, a layer that electrically functions as p-type is referred to as a p-type layer, and a layer that electrically functions as n-type is referred to as an n-type layer. On the other hand, when a specific impurity such as Si, Zn, S, Sn, or Mg is not intentionally added and does not electrically function as p-type or n-type, it is referred to as “i-type” or “undoped”. .. The undoped III-V group compound semiconductor layer may contain inevitable impurities in the manufacturing process. Specifically, when the dopant concentration is low (for example, less than 7.6×10 ¹⁵ atoms/cm ³ ), it is treated as “undoped” in this specification. The value of the impurity concentration of Si, Zn, S, Sn, Mg, etc. is based on SIMS analysis. Similarly, the n-type dopant (eg, Si, S, Te, Sn, Ge, O, etc.) impurity concentration (“dopant concentration”) value of the active layer is also based on SIMS analysis. Since the value of the dopant concentration changes greatly near the boundary of each semiconductor layer, the value of the dopant concentration at the center of the active layer in the thickness direction is taken as the value of the dopant concentration.

<Thickness and composition of each layer>
Further, the total thickness of each layer formed can be measured by using an optical interference type film thickness meter. Furthermore, the thickness of each layer can be calculated by observing the cross section of the grown layer with an optical interference type film thickness meter and a transmission electron microscope. When the thickness of each layer is as small as several nanometers, which is similar to a superlattice structure, the thickness can be measured by using TEM-EDS. Regarding the phase ratio, the value obtained by SIMS analysis after exposing the light emitting layer is used. In the cross-sectional view of each layer, when a predetermined layer has an inclined surface, the thickness of the layer is the maximum height from the flat surface of the layer immediately below the layer.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In principle, the same components are designated by the same reference numerals, and duplicate description will be omitted. In each drawing, the vertical and horizontal ratios of the substrate and each layer are exaggerated from the actual ratios for convenience of description.

(Semiconductor light emitting device)
Reference is made to FIG. 1, which illustrates one embodiment of the present invention. The semiconductor light emitting device according to the present invention includes a light emitting layer 50 having a laminated structure in which a first III-V compound semiconductor layer 51 and a second III-V compound semiconductor layer 52 having different composition ratios are repeatedly laminated. Hereinafter, the first III-V compound semiconductor layer 51 and the second III-V compound semiconductor layer 52 are abbreviated as the first layer 51 and the second layer 52, respectively. In the semiconductor light emitting device according to the present invention, the group III element in the first layer 51 and the second layer 52 is one or more selected from the group consisting of Al, Ga and In, and the first layer The group V element in 51 and the second layer 52 is one or more selected from the group consisting of As, Sb, and P.

In the following, the composition of the III-V group compound semiconductor of the first layer 51 is (In _a1 Ga _b1 Al _c1 )(P _x1 As _y1 Sb _z1 ); c ₁ =1-a ₁ -b ₁ , z ₁ =1- denoted as _{x 1 -y 1, 0 ≦ a} 1 ≦ 1,0 ≦ b 1 ≦ 1,0 ≦ c 1 ≦ 1,0 ≦ x 1 ≦ 1,0 ≦ y 1 ≦ 1,0 ≦ z 1 ≦ 1 .. Similarly, the composition of the group III-V compound semiconductor of the second layer _{52 (In a2 Ga b2 Al c2} ) (P x2 As y2 Sb z1); c 2 = 1-a 2 -b 2, z 2 = 1- expressed as _{x 2 -y 2, 0 ≦ a} 2 ≦ 1,0 ≦ b 2 ≦ 1,0 ≦ c 2 ≦ 1,0 ≦ x 2 ≦ 1,0 ≦ y 2 ≦ 1,0 ≦ z 2 ≦ 1 .. Each of the first layer 51 and the second layer 52 according to the present invention is composed of one or two or more elements from group III elements and one or two or more elements from group V elements, for a total of three or more elements.

Further, in the present invention, the composition wavelength difference between the composition wavelength of the first layer 51 and the composition wavelength of the second layer 52 is set to 50 nm or less, and the lattice constant of the first layer 51 and the lattice constant of the second layer 52. The ratio of the difference in the lattice constant between and is set to 0.05% or more and 0.60% or less. The composition wavelength difference and the lattice constant difference are absolute values. The ratio of the difference in lattice constant is a value obtained by dividing the absolute value of the difference in lattice constant between the first layer 51 and the second layer 52 by the average value of the lattice constants between the first layer 51 and the second layer 52. When a third layer 53 to be described later is provided, the adjacent layers are calculated, and the absolute value of the lattice constant difference between the first layer 51 and the third layer 53 is calculated as the absolute value of the lattice constant between the first layer 51 and the third layer 53. A value divided by the average value and a value obtained by dividing the absolute value of the lattice constant difference between the third layer 53 and the second layer 52 by the average value of the lattice constants of the third layer 53 and the second layer 52, and for each value 0.05% or more and 0.60% or less. The inventors of the present invention have found that when the composition wavelength difference and the lattice constant difference based on the composition ratio of the first layer 51 and the second layer 52 satisfy this relationship, the light emission output of the semiconductor light emitting device can be significantly increased as compared with the conventional case. Was confirmed experimentally.

The reason why the light emission output of the semiconductor light emitting device is increased by the composition wavelength difference and the lattice constant difference satisfying the above conditions is not clear, and the reason why the present invention effect is obtained, although the present invention is not bound by theory The present inventors consider the following. When the composition wavelength difference is 50 nm or less, there is only a barrier that allows holes to be easily exceeded at the junction temperature during energization (light emission), and a double band with no composition wavelength difference as a band structure during energization (light emission). The structure resembles a heterostructure. Further, if the composition wavelength difference is 30 nm or less (more preferably 25 nm or less), there is only a low barrier that can be easily exceeded even with heat energy at room temperature when not energized. It approaches a double hetero structure with no wavelength difference, and becomes a structure almost the same as the double hetero structure. Then, the barrier height is lowered by approaching the double hetero structure, and the splitting of the valence band is caused by the strain due to the difference in lattice constant, so that an electron confinement effect similar to the quantum well structure is obtained, so that the light emission output is It is expected to increase.

Here, in order to more reliably obtain the effect of the present invention, the ratio of the difference in lattice constant between the first layer 51 and the second layer 52 is preferably 0.05 or more, and is 0.3% or more. More preferably, the difference in composition wavelength between the first layer 51 and the second layer 52 may be 20 nm or less, or may be 1 nm or less, and the composition wavelength difference is the same (that is, the composition wavelength difference is 0 nm).

Further, it is more preferable that the group III element is two kinds of Ga and In and the group V element is two or more kinds selected from the group consisting of As, Sb and P. Further, a quaternary compound semiconductor of InGaAsP (hereinafter, InGaAsP semiconductor) is more preferable. If the III-V group compound semiconductor materials of the first layer 51 and the second layer 52 are both InGaAsP quaternary compound semiconductors, the effect of the present invention can be reliably obtained. In this case, the Al composition ratio c ₁ and the Sb composition ratio z ₁ in the first layer 51 are both 0, and the composition formula (In _a1 Ga _b1 )(P _x1 As _y1 ); b ₁ =1-a ₁ , _{y 3 = 1-x 1,} 0 ≦ a 1 ≦ 1,0 ≦ b 1 ≦ 1,0 ≦ x 1 ≦ 1,0 ≦ y 1 ≦ 1 becomes and, the composition ratio of Al in the second layer 52 c ₂ And the composition ratio z _{2 of} Sb are both 0, and the composition formula (In _a2 Ga _b2 )(P _x2 As _y2 ); b ₂ =1-a ₂ , y ₂ =1-x ₂ , 0≦a ₂ ≦1 , 0≦b ₂ ≦1, 0≦x ₂ ≦1, 0≦y ₂ ≦1.

The laminated structure of the light emitting layer 50 in the semiconductor light emitting device according to the present invention may be composed of only the first layer 51 and the second layer 52, or may be provided with a further III-V group compound semiconductor layer. For example, as shown in FIG. 2 showing another embodiment of the present invention, in the laminated structure of the light emitting layer 50, the third III-V group compound semiconductor layer 53 is provided between the first layer 51 and the second layer 52. (Hereinafter, abbreviated as the third layer 53) may be further provided. A preferable aspect of the third layer 53 will be described.

Following the first layer 51 and the second layer 52, the composition of the III-V group compound semiconductor of the third layer 53 is (In _a3 Ga _b3 Al _c3 )(P _x3 As _y3 Sb _z3 ); c ₃ =1-a _{3 -b 3, z 3 = 1-} x 3 -y 3, 0 ≦ a 3 ≦ 1,0 ≦ b 3 ≦ 1,0 ≦ c 3 ≦ 1,0 ≦ x 3 ≦ 1,0 ≦ y 3 ≦ 1, It is expressed as 0≦z ₃ ≦1. When the third layer 53 is provided in the light emitting layer 50, the third layer 53 is formed of one or more kinds of the group III elements described above and a group V element, like the first layer 51 and the second layer 52. It is preferably composed of three or more elements selected from one kind or two or more kinds. Further, in this case, the composition wavelength difference between the first layer 51 and the third layer 53, the third layer 53 and the second layer 52, the second layer 52 and the first layer 51 which are adjacent to each other is 50 nm or less, and It is preferable that the ratios of the lattice constant differences between adjacent ones are both 0.05% or more and 0.60% or less.

Further, from the viewpoint of more reliably obtaining the effect of the present invention, when the third layer 53 is provided, the III-V group compound semiconductor material of the third layer 53 has a group III element of Ga, In, and a group V element. The elements are preferably two or more selected from the group consisting of As, Sb and P, and more preferably a quaternary compound semiconductor of InGaAsP (hereinafter, InGaAsP-based semiconductor). In this case, both the Al composition ratio c ₃ and the Sb composition ratio z ₃ in the third layer 53 are zero.

-Film thickness-
The total thickness of the light emitting layer 50 is not limited, but may be, for example, 1 μm to 8 μm. Further, the film thickness of each of the first layer 51, the second layer 52, and the third layer 53 in the laminated structure of the light emitting layer 50 is not limited, but may be, for example, about 1 to 15 nm. The film thickness of each layer may be the same or different. Further, the film thicknesses of the first layers 51 may be the same or different in the laminated structure. The same applies to the film thickness of the second layers 52 and the film thickness of the third layers 53. However, the light emitting layer 50 has a superlattice structure in which the first layers 51 have the same thickness and the second layers 52 have the same thickness (third layers also when the third layer 53 is provided). That is one of the preferred embodiments of the present invention.

-Number of laminated sets-
Please refer to FIG. The number of sets of both the first layer 51 and the second layer 52 is not limited, but may be, for example, 3 to 50 sets. One end of the laminated structure can be the first layer 51 and the other end can be the second layer 52. In this case, the number of sets of the first layer 51 and the second layer 52 is described as n sets (n is a natural number).

Further, one end of the laminated structure may be the first layer 51, a repeating structure of the second layer 52 and the first layer 51 may be provided, and the other end may be the first layer 51. Alternatively, on the contrary, both ends may be the second layers 52. In this case, the number of sets of the first layer 51 and the second layer 52 is expressed as n (n is a natural number), and n. We will say that there are 5 groups. In FIG. 1, both ends of the laminated structure are shown as first layers 51.

The number of sets when the third layer 53 is provided in the laminated structure as shown in FIG. 2 is not limited, and may be 3 to 50 as in the case of referring to FIG. Although FIG. 2 illustrates a case where the number of stacked groups is n, the number of stacked groups is not limited to this.

-Composition ratio-
As long as the conditions of the composition wavelength difference and the lattice constant difference are satisfied, the composition ratios a, b, c, x, y of the III-V group compound semiconductor in each of the first layer 51, the second layer 52 and the third layer 53. , Z is not limited. However, in order to suppress the deterioration of the crystallinity of the light emitting layer, the selection range of the composition ratio is such that the ratio of the lattice constant difference between the growth substrate and the light emitting layer (first layer and second layer) is 1 in each case. % Or less is preferable. That is, the absolute value of the lattice constant difference between the growth substrate and the first layer is divided by the average value of the growth substrate and the first layer, and the absolute value of the lattice constant difference between the growth substrate and the second layer is used for the growth. The value divided by the average value of the substrate and the second layer is preferably 1% or less. For example, when the emission center wavelength is 1000 to 1900 nm and the growth substrate is an InP substrate, the In composition ratio a in each layer is 0.0 to 1.0, the Ga composition ratio b is 0.0 to 1.0, and the Al composition ratio c is The composition ratio x of 0.0 to 0.35, P can be 0.0 to 0.95, the composition ratio y of As can be 0.15 to 1.0, and the composition ratio z of Sb can be 0.0 to 0.7. It may be appropriately set within these ranges so as to satisfy the condition of the ratio of the composition wavelength difference and the lattice constant difference. The above emission center wavelength is merely an example. For example, in the case of a quaternary compound semiconductor of InGaAsP (hereinafter, InGaAsP-based semiconductor), the emission center wavelength can be set within the range of 1000 nm to 2200 nm and includes Sb. In this case, infrared rays having a longer wavelength (11 μm or less) can be used.

-Dopant-
Although the dopant of each layer in the light emitting layer 50 is not limited, it is preferable that all of the first layer 51, the second layer 52, and the third layer 53 be i-type in order to surely obtain the effect of the present invention. However, each layer may be doped with an n-type or p-type dopant.

Hereinafter, although not intended to limit the specific configuration of the semiconductor light emitting device of the present invention, specific embodiments that the semiconductor light emitting device of the present invention can further include will be described. A semiconductor light emitting device 100 according to an exemplary embodiment will be described with reference to FIG.

A semiconductor light emitting device 100 according to an embodiment of the present invention includes at least a light emitting layer 50 having the above-described laminated structure, and further includes a supporting substrate 10, an intervening layer 20, a first conductivity type III-V group compound semiconductor layer 30, and a first conductive type III-V compound semiconductor layer 30. It is preferable that the spacer layer 41, the light emitting layer 50, the second spacer layer 42, and the second conductivity type III-V group compound semiconductor layer 70 have a desired configuration in this order. Further, the semiconductor light emitting device 100 may further include a second electrode 80 on the second conductivity type III-V group compound semiconductor layer 70 and a first electrode 90 on the back surface of the support substrate 10. If the first conductivity type is n-type, the second conductivity type is p-type, and conversely, if the first conductivity type is p-type, the second conductivity type is n-type. Hereinafter, an aspect in which the first conductivity type is n-type and the second conductivity type is p-type will be described. Hereinafter, for convenience of description, the first conductivity type III-V group compound semiconductor layer 30 is referred to as an n-type semiconductor layer 30, and the second conductivity type III-V group compound semiconductor layer 70 is referred to as a p-type semiconductor layer 70. Then, the present embodiment will be described according to this specific example. By sandwiching the light emitting layer 50 between the n-type semiconductor layer 30 and the p-type semiconductor layer 70, a structure similar to a double hetero structure can be obtained, and when the light emitting layer 50 is energized, electrons and positive electrons are generated in the light emitting layer 50. Light is emitted by binding at the holes.

<Growth substrate>
The growth substrate may be appropriately selected from compound semiconductor substrates such as InP substrate, InAs substrate, GaAs substrate, GaSb substrate and InSb substrate according to the composition of the light emitting layer 50. The conductivity type of each substrate preferably corresponds to the conductivity type of the semiconductor layer on the growth substrate, and an n-type InP substrate and an n-type GaAs substrate can be exemplified as the compound semiconductor substrate applicable to this embodiment. ..

<Supporting substrate>
As the support substrate 10, a growth substrate for growing the light emitting layer 50 on the support substrate 10 can be used. When the bonding method described below is used, various substrates different from the growth substrate may be used as the supporting substrate 10.

<Intervening layer>
The intervening layer 20 may be provided on the support substrate 10. The intervening layer 20 can be a III-V group compound semiconductor layer. It can be used as an initial growth layer for epitaxially growing a semiconductor layer on the support substrate 10 as a growth substrate. Further, for example, it can also be used as a buffer layer for buffering lattice distortion between the support substrate 10 as a growth substrate and the n-type semiconductor layer 30. Further, it can also be used as an etching stop layer by changing the semiconductor composition while lattice-matching the growth substrate and the intervening layer 20. For example, when the support substrate is an n-type InP substrate, the intervening layer 20 is preferably an n-type InGaAs layer. In this case, in order to make the intervening layer 20 lattice-match with the InP growth substrate, the In composition ratio in the group III element is preferably 0.3 to 0.7, and more preferably 0.5 to 0.6. preferable. Further, if the composition ratio is such that the lattice constant is close to that of the InP substrate as in InGaAs, AlInAs, AlInGaAs, or InGaAsP may be used. The intervening layer 20 may be a single layer or a composite layer with another layer (for example, a superlattice layer).

<n-type semiconductor layer>
An n-type semiconductor layer 30 can be provided on the support substrate 10 and, if necessary, the intervening layer 20, and the n-type semiconductor layer 30 can be used as an n-type cladding layer. The composition of the III-V group compound semiconductor of the n-type semiconductor layer 30 may be appropriately determined according to the composition of the III-V group compound semiconductor of the light emitting layer 50. When the light emitting layer 50 is composed of an InGaAsP-based semiconductor, for example, an n-type InP layer can be used. The n-type semiconductor layer 30 may have a single layer structure or a composite layer in which a plurality of layers are laminated. The thickness of the n-type clad layer can be exemplified by 1 μm to 5 μm.

<Spacer layer>
It is also preferable to provide the first spacer layer 41 and the second spacer layer 42 between the light emitting layer 50 and the n-type semiconductor layer 30 and the p-type semiconductor layer 70, respectively. The first spacer layer 41 can be an undoped or n-type III-V group compound semiconductor layer, and for example, an i-type InP spacer layer is preferably used. On the other hand, the p-side second spacer layer 42 is preferably an undoped III-V group compound semiconductor layer, and for example, an i-type InP spacer layer can be used. By providing the undoped spacer layer 42, it is possible to prevent unnecessary diffusion of the dopant between the light emitting layer 50 and the p-type layer. The thickness of each spacer layer 41, 42 is not limited, but may be, for example, 5 to 500 nm.

<p-type semiconductor layer>
The p-type semiconductor layer 70 may be provided on the light emitting layer 50 and the second spacer layer 42 as necessary. The p-type semiconductor layer 70 may include a p-type cladding layer 71 and a p-type contact layer 73 in order from the light emitting layer 50 side. It is also preferable to provide the intermediate layer 72 between the p-type cladding layer 71 and the p-type contact layer 73. By providing the intermediate layer 72, the lattice mismatch between the p-type cladding layer 71 and the p-type contact layer 73 can be relaxed. The composition of the III-V group compound semiconductor of the p-type semiconductor layer 70 may be appropriately determined according to the composition of the III-V group compound semiconductor of the light emitting layer 50. When the light emitting layer 50 is composed of an InGaAsP-based semiconductor, p-type InP is used as the p-type cladding layer, p-type InGaAsP is used as the intermediate layer, and p-type InGaAs that does not contain P is used as the p-type contact layer 73. You can Although the film thickness of each layer of the p-type semiconductor layer 70 is not particularly limited, the film thickness of the p-type cladding layer 71 may be 1 μm to 5 μm, and the film thickness of the intermediate layer 72 may be 50 to 200 nm. The thickness of the p-type contact layer 73 may be 50 nm to 200 nm.

<Electrode>
A first electrode 80 and a second electrode 90 can be provided on the p-type semiconductor layer 70 and on the back surface of the support substrate 10, respectively. The metal material for forming each electrode is a metal such as Ti, Pt, or Au, A general metal such as a metal (Sn or the like) forming a eutectic alloy with gold can be used. Furthermore, the electrode pattern of each electrode is arbitrary and is not limited at all.

So far, the embodiment in which the compound semiconductor substrate is used as the growth substrate and the growth substrate is used as it is as the support substrate 10 has been described, but the present invention is not limited thereto. As a supporting substrate of the semiconductor light-emitting device of the present invention, after forming each semiconductor layer on the growth substrate, while removing the growth substrate by a bonding method, a semiconductor substrate such as Si substrate, such as Mo or W or Kovar It is also possible to bond a metal substrate, various submount substrates using AlN or the like, and use this as a supporting substrate (hereinafter referred to as "bonding method", see JP-A-2018-006495).

When the bonding method is used, the semiconductor light emitting device 100 may be provided with layers other than the III-V group compound semiconductor in addition to the electrodes. For example, when the bonding method is used, the intervening layer 20 made of a metal material can be formed on the supporting substrate 10 made of a Si substrate, and the p-type semiconductor layer 70, the light emitting layer 50, and the n-type semiconductor layer 30 are formed on the intervening layer 20. It is formed sequentially. The intervening layer 20 can be used as a metal reflecting layer on the support substrate 10. Further, the semiconductor light emitting device 100 may be provided with a dielectric layer including an ohmic electrode portion in addition to the III-V group compound semiconductor layer, if necessary. The dielectric material is SiO ₂ , SiN, ITO or the like.

As described above, in the above-described embodiment, the case where the first conductivity type semiconductor layer is n-type and the second conductivity type semiconductor layer is p-type has been described as an example, but the conductivity type of each layer is n-type. It is of course understood that the /p type can be reversed from the above embodiments.

(Method of manufacturing semiconductor light emitting device)
In the method for manufacturing a semiconductor light emitting device according to the present invention, the first step of forming the first layer 51, the second step of forming the second layer 52, and the first step and the second step are repeated to perform the light emitting layer. A light emitting layer forming step of forming 50. It may further include a third step of forming the third layer 53. In this case, in the light emitting layer forming step, the first step of forming the first layer 51, the third step of forming the third layer 53, and the second step of forming the second layer 52 can be repeated.

In addition, a step of forming each layer of the semiconductor light emitting device 100 described with reference to FIG. 3 may be included as necessary. The III-V group compound semiconductor materials that can be used as the first layer 51 and the second layer 52, the respective conditions of the composition wavelength difference and the lattice constant difference thereof, the respective film thicknesses, the number of laminated layers, etc. have been described above. As such, redundant description will be omitted.

Each of the III-V compound semiconductor layers is a known thin film growth method such as a metal organic chemical vapor deposition (MOCVD) method, a molecular beam epitaxy (MBE) method, or a sputtering method. Can be formed by. In the case of an InGaAsP-based semiconductor, for example, trimethylindium (TMIn) as an In source, trimethylgallium (TMGa) as a Ga source, arsine (AsH ₃ ) as an As source, and phosphine (PH ₃ ) as a P source are mixed at a predetermined ratio. And vapor-phase growth of these source gases using a carrier gas, the InGaAsP-based semiconductor layer can be epitaxially grown to a desired thickness according to the growth time. When Al is used as the group III element, trimethyl aluminum (TMA) or the like may be used as the Al source, and when Sb is used as the group V element, TMSb (trimethyl antimony) or the like may be used as the Sb source. Furthermore, when p-type or n-type dopant is applied to each semiconductor layer, a gas of a dopant source containing Si, Zn, or the like as a constituent element may be further used as desired.

A known method can be used to form the metal layers such as the first and second electrodes, and for example, a sputtering method, an electron beam evaporation method, a resistance heating method, or the like can be used. When the bonding method is used, if a dielectric layer is formed, a known film forming method such as a plasma CVD method or a sputtering method may be applied, and if necessary, a known etching method may be used to form unevenness. It is also possible.

When the bonding method (refer to the above-mentioned Japanese Patent Laid-Open No. 2018-006495) is used, the semiconductor light emitting device can be manufactured, for example, as follows.

First, each layer of the III-V group compound semiconductor layer including the etching stop layer, the n-type semiconductor layer 30, the light emitting layer 50, the p-type cladding layer 71, the intermediate layer 72, and the p-type contact layer 73 is sequentially formed on the growth substrate. To do. Next, on the p-type contact layer 73, island-shaped dispersed p-type ohmic electrode portions are formed. After that, a resist mask is formed on the p-type ohmic electrode portion and its periphery, and the p-type contact layer 73 other than the place where the ohmic electrode portion is formed is removed by wet etching or the like to expose the intermediate layer 72. Then, a dielectric layer is formed on the intermediate layer 72. Further, the p-type ohmic electrode portion and the dielectric layer around the p-type ohmic electrode portion are removed by etching to expose the intermediate layer 72, and a metal reflection layer is formed on the intermediate layer 72.

On the other hand, using a conductive Si substrate or the like as the support substrate, a metal bonding layer is formed on the support substrate. The metal reflection layer and the metal bonding layer are arranged opposite to each other and bonded by heat compression or the like. Then, the etching stop layer is etched to expose the n-type semiconductor layer 30 while the growth substrate is being removed by etching. By forming an upper surface electrode on the n-type semiconductor layer 30, junction-type semiconductor light emission can be obtained. As described above, the conductivity type n type/p type of each layer may be reversed from the above example.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

(Experimental example 1)
The semiconductor light emitting devices according to the following Inventive Example 1 and Comparative Examples 1 to 3 were manufactured by a bonding method with the target emission center wavelength set to 1300 nm.

<Invention Example 1>
For the respective constitutions of the III-V group compound semiconductor layers of the semiconductor light emitting device 100 according to Inventive Example 1, reference numerals in FIG. An S-doped n-type InP substrate was used as a growth substrate. An n-type InP layer having a thickness of 100 nm and an n-type In _0.57 Ga _0.43 As layer having a thickness of 20 nm (each of which is formed on the (100) plane of an n-type InP substrate (S-doped, dopant concentration 2×10 ¹⁸ atoms/cm ³ ) Initial growth layer and etching stop layer), a 2000 nm thick n-type InP layer (n-type semiconductor layer 30 as an n-type cladding layer), a 100 nm thick i-type InP layer (first spacer layer 41), A light emitting layer 50 described later, an i-type InP layer having a thickness of 320 nm (second spacer layer 42), a p-type InP layer having a thickness of 4800 nm (p-type cladding layer 71), and a p-type In _0.8 Ga _0.2 As _{0.5 having} a thickness of 50 nm. A P _0.5 layer (intermediate layer 72) and a p-type In _0.57 Ga _0.43 As layer (p-type contact layer 73) having a thickness of 100 nm were sequentially formed by the MOCVD method. The n-type InP layer and the n-type InGaAs layer (respectively the initial growth layer and the etching stop layer) and the n-type InP layer (the n-type semiconductor layer 30 as the n-type cladding layer) are Si-doped, and the dopant concentration is 7×10 7. ^{It was set to 17} atoms/cm ³ . The p-type InP layer (p-type cladding layer 71) was Zn-doped, and the dopant concentration was 1×10 ¹⁸ atoms/cm ³ . The p-type InGaAsP layer (intermediate layer 72) and the p-type InGaAs layer (p-type contact layer 73) were Zn-doped, and the dopant concentration was 1×10 ¹⁹ atoms/cm ³ .

When forming the light emitting layer 50, the i-type In _a1 Ga _b1 As _x1 P _y1 layer (first layer 51) is first formed, and then the i-type In _a2 Ga _b2 As _x2 P _y2 layer (second layer 52) and i 10 types of In _a1 Ga _b1 As _x1 P _y1 layers (first layer 51) were alternately laminated to form a laminated structure of 10.5 sets. That is, both ends of the light emitting layer 50 are i-type In _a1 Ga _b1 As _x1 P _y1 layers (first layer 51). The i-type In _a1 Ga _b1 As _x1 P _y1 layer (first layer 51) is In _0.675 Ga _0.325 As _0.689 P _0.311 having a thickness of 8 nm. That is, the In composition ratio (a1) is 0.675, the Ga composition ratio (b1) is 0.325, the As composition ratio (x1) is 0.689, and the P composition ratio (y1) is 0.311. The i-type In _a2 Ga _b2 As _x2 P _y2 layer (second layer 52) is In _0.633 Ga _0.367 As _0.716 P _0.284 having a thickness of 5 nm. That is, the In composition ratio (a2) is 0.633, the Ga composition ratio (b2) is 0.367, the As composition ratio (x2) is 0.716, and the P composition ratio (y2) is 0.284. The total thickness of the light emitting layer is 138 nm. In addition, each composition of each layer in the above-mentioned invention example 1 is a value measured by SIMS analysis. Regarding each layer of the light emitting layer, SIMS analysis was performed after exposing the light emitting layer to confirm the solid phase ratio of each layer.

Island-shaped dispersed p-type ohmic electrode portions (Au/AuZn/Au, total thickness: 530 nm) were formed on the p-type contact layer. In forming the island-shaped pattern, a resist pattern was formed, an ohmic electrode was then deposited, and the resist pattern was lifted off. The contact area ratio with the p-type contact layer is 4.5%, and the chip size is 380 μm square.

Next, a resist mask is formed on the p-type ohmic electrode portion and its periphery, and the p-type contact layer other than the place where the ohmic electrode portion is formed is removed by tartaric acid-hydrogen peroxide-based wet etching to expose the intermediate layer. Let After that, a dielectric layer (thickness: 700 nm) made of SiO ₂ was formed on the entire surface of the intermediate layer 72 by the plasma CVD method. Then, a window pattern having a shape with a width of 3 μm added in the width direction and the longitudinal direction is formed with a resist in the upper region of the p-type ohmic electrode portion, and the p-type ohmic electrode portion and the dielectric layer around it are wetted with BHF. It was removed by etching to expose the intermediate layer 72.

Next, a metal reflective layer (Al/Au/Pt/Au) was formed on the entire surface of the intermediate layer 72 by vapor deposition. The thickness of each metal layer of the metal reflection layer is 10 nm, 650 nm, 100 nm, and 900 nm in order.

On the other hand, a metal bonding layer (Ti/Pt/Au) was formed on a conductive Si substrate (thickness: 300 μm) serving as a supporting substrate. The thickness of each metal layer of the metal bonding layer is 650 nm, 10 nm, and 900 nm in order.

The metal reflection layer and the metal bonding layer were arranged to face each other, and heat compression bonding was performed at 300°C. Then, the n-type InP substrate was removed by wet etching with a hydrochloric acid diluting solution, and the etching stop layer was removed by wet etching using a sulfuric acid-hydrogen peroxide system to expose the n-type cladding layer.

On the n-type clad layer, an n-type electrode (Au (thickness: 10 nm)/Ge (thickness: 33 nm)/Au (thickness: 57 nm)/Ni (thickness: 34 nm)/ Au (thickness: 800 nm)/Ti (thickness: 100 nm)/Au (thickness: 1000 nm)) was formed by resist pattern formation, n-type electrode vapor deposition, and resist pattern lift-off. Further, a pad portion (Ti (thickness: 150 nm)/Pt (thickness: 100 nm)/Au (thickness: 2500 nm)) was formed on the n-type electrode to form a pattern of the upper surface electrode.

Finally, the semiconductor layer between each element (width 60 μm) was removed by mesa etching to form a dicing line. Then, a back surface electrode (Ti (thickness: 10 nm)/Pt (thickness: 50 nm)/Au (thickness: 200 nm)) is formed on the back surface side of the Si substrate, and dicing is performed to divide the chip into individual pieces. A semiconductor light emitting device according to Example 1 was produced.

<Comparative Examples 1 to 3>
A semiconductor light emitting device was formed according to the bonding method in the same manner as in Inventive Example 1 except that the composition ratios of the first layer 51 and the second layer 52 in Inventive Example 1 were changed as shown in Table 2. Including the invention example 1, Table 2 shows the composition ratio of the first layer 51 and the second layer 52, and the composition wavelength and the lattice constant converted from them. Further, Table 2 shows the ratio of the composition wavelength difference and the lattice constant difference as an absolute value. The second layer 52 of Comparative Example 1 is an i-type InP layer, and the other layers constituting the light emitting layer are i-type InGaAsP layers.

(Experimental example 2)
The semiconductor light emitting elements according to the following Inventive Example 2 and Comparative Examples 4 to 8 were manufactured by the bonding method with the target emission center wavelength set to 1460 nm.

<Invention Example 2, Comparative Examples 4 to 8>
Except that the composition ratios of the first layer 51 and the second layer 52 in Inventive Example 1 were changed as shown in Table 3, the semiconductor light emitting devices according to Inventive Example 2 and Comparative Examples 4 to 8 were performed in the same manner as in Inventive Example 1. It was formed according to the joining method. The second layer 52 of Comparative Example 4 is an i-type InP layer. Further, in Table 3, the ratio of the composition wavelength difference and the lattice constant difference is shown as in Table 2.

<Evaluation 1: Emission output evaluation>
Forward voltage Vf when a current of 20 mA is applied to the semiconductor light emitting elements according to each of Inventive Examples 1 and 2 and Comparative Examples 1 to 8 by using a constant current voltage power source, the light emission output Po by the integrating sphere, and the light emission center wavelength. λp was measured, and the average value of the measurement results of three samples was obtained. The results are shown in Table 4. In addition, a graph showing the relationship between the composition wavelength difference and the emission output Po is shown in FIG. Further, a graph showing the relationship between the composition wavelength difference and the forward voltage Vf is shown in FIG.

<Evaluation 2: Luminance output maintenance rate>
The initial light emission output of the integrating sphere was measured immediately after the semiconductor light emitting device was manufactured (average of three samples), and then the semiconductor light emitting device was continuously energized with 20 mA at room temperature for 1000 hours, and then the light emitting output of the integrating sphere was measured. (Average of 3 samples). The results are shown in Table 4.

From Table 4 and FIG. 4, it is confirmed that the emission output is improved when the composition wavelength difference and the lattice constant difference according to the conditions of the present invention are satisfied. Further, it is confirmed from FIG. 5 that the forward voltage in each of Examples 1 and 2 was as good as or better than the comparative example in each experimental example. It is also confirmed that the emission output maintenance ratios in Examples 1 and 2 were as good as or better than those in the comparative examples of the respective experimental examples.

10 Supporting Substrate 20 Intervening Layer 30 First-conductivity-type Semiconductor Layer (n-type Semiconductor Layer)
41 First Spacer Layer 42 Second Spacer Layer 50 Light Emitting Layer 51 First III-V Group Compound Semiconductor Layer (First Layer)
52 Second III-V Group Compound Semiconductor Layer (Second Layer)
53 Third III-V compound semiconductor layer (third layer)
70 Second conductivity type semiconductor layer (p type semiconductor layer)
80 first electrode 90 second electrode 100 semiconductor light emitting element

Claims (9)

A semiconductor light emitting device comprising a light emitting layer having a laminated structure in which a first III-V compound semiconductor layer and a second III-V compound semiconductor layer having different composition ratios are repeatedly laminated,
The group III element in the first and second group III-V compound semiconductor layers is one or more selected from the group consisting of Al, Ga and In, and the first and second groups The group V element in the III-V group compound semiconductor layer is one kind or two or more kinds selected from the group consisting of As, Sb and P,
Each of the first and second III-V group compound semiconductor layers is composed of three or more elements selected from the group III element and the group V element,
A difference in composition wavelength between the composition wavelength of the first III-V compound semiconductor layer and the composition wavelength of the second III-V compound semiconductor layer is 50 nm or less, and the first III-V A semiconductor light emitting device, characterized in that the ratio of the lattice constant difference between the lattice constant of the group compound semiconductor layer and the lattice constant of the second III-V compound semiconductor layer is 0.05% or more and 0.60% or less. .. The semiconductor light emitting device according to claim 1, wherein a ratio of the lattice constant difference is 0.3% or more. The semiconductor light emitting device according to claim 1, wherein the composition wavelength difference between the first and second III-V compound semiconductor layers is 30 nm or less. The first and second III-V compound semiconductor layers are each composed of four or more elements selected from the group III element and the group V element. 2. The semiconductor light emitting device according to item 1. Among the elements constituting the four or more elements, the group III element is Ga, In, and the group V element is two or more elements selected from the group consisting of As, Sb, P. The semiconductor light emitting device according to. The semiconductor light emitting device according to claim 1, wherein both the first and second III-V group compound semiconductor layers are quaternary compound semiconductors of InGaAsP. In the laminated structure of the light emitting layer, a third III-V compound semiconductor layer is further provided between the first and second III-V compound semiconductor layers,
The third group III-V compound semiconductor layer is composed of four or more elements selected from the group III elements and the group V elements,
The composition wavelength difference between the adjacent first, second and third III-V compound semiconductor layers is 50 nm or less, and
7. Any of claims 1 to 6, wherein the ratio of the difference in lattice constant between the first, second and third III-V group compound semiconductor layers adjacent to each other is 0.05% or more and 0.60% or less. 2. The semiconductor light emitting device according to item 1. The semiconductor light emitting device according to claim 7, wherein the third III-V group compound semiconductor layer is a quaternary compound semiconductor of InGaAsP. A method for manufacturing the semiconductor light-emitting device according to claim 1, comprising:
A first step of forming the first III-V compound semiconductor layer,
A second step of forming the second III-V compound semiconductor layer,
A method of manufacturing a semiconductor light emitting device, comprising: a light emitting layer forming step of forming the light emitting layer by repeating the first step and the second step.

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